The end of this is beyond me. Can anybody translate and explain how they get their reading?

"Then is all that is just also holy? Or is that which is holy all just, whereas that which is just is not all holy, but some of it holy, some [of it] something else entirely?"

I'll explain the grammar first:

Both καὶ's are adverbial. The first just means "also"; the second goes closely with ἄλλο and means "[something] even different" or "[something] else even".

For the last part, remember that a bare article when used with correlated μὲν...δέ usually means "some...some [the rest/others]". The αὐτοῦ is partitive, referring back to τὸ δίκαιον, and it should be understood with the τὸ δέ that comes afterward as well.

It's a bit confusing because you have μὲν...δέ earlier in the sentence, too, but there the meaning is simply "on the one hand...on the other". The difference can be accounted for by the inclusion of the attributive adjectives ὅσιον and δίκαιον, respectively, immediately after the first μὲν and δὲ. The ὅσιον that comes after the second μὲν cannot be an attributive adjective, however, both because that would leave the clause incomplete (without a predicative adjective the verb ἐστί cannot be supplied), and because αὐτοῦ separates it from the article (τὸ αὐτοῦ ὅσιον is invalid as a single unit because αὐτοῦ, whether possessive or partitive, can only be in a predicate position in Attic*: "what of it is holy" would have to be either αὐτοῦ τὸ ὅσιον or τὸ ὅσιον αὐτοῦ)

As for the meaning, it seems difficult at first glance but this is really just elementary formal logic. If you understand it as a syllogism with three terms (A = what is just; B = what is holy; C = what isn't holy), all he's saying is this:

"Is it that all A is B? Or is it that all B is A, and not all A is B, but only some of A is B, and some of A is C instead?"

If you think about it it makes perfect sense.

pster wrote:And here is another that I'm struggling with, mostly the beginning of the phrase:

The first part (up to the colon) seems to be: "Yet it seems to me, Socrates, that what was said [what you said?] lacks just a little [τι = somewhat] of the same jest". The rest is rather unclear to me without context: not the grammar so much as what the heck he's talking about. Maybe you could explain it? I've not read Euthyphro before.

*This is true for the genitives of the other personal pronouns (ἐμοῦ, σοῦ, ἡμῶν, etc.) as well, but the genitives of reflexive and demonstrative pronouns regularly have attributive position. On the other hand, the possessive adjectives (ἐμός, σός, ἡμέτερος, etc.) always have attributive position.

Socrates is confusing Euthyphro. Euthyphro says that the words are moving around and that Socrates is like Deadelus. Socrates picks up on the Deadelus reference seemingly alluding to the fact that his deme was linked to Daedalus; and so the joke would be a good one were the claims being made Socrates' own. But since all of the claims are Euthyphro's--since in the early Platonic dialogues we get the genuine Socratic elenchus--Euthyphro must be the Daedalus. Euthyphro tacitly accepts that they are his words but insists that Socrates is the one making them move so he must be the Daedalus. That brings us to the end of the quoted passage. In the very next lines Socrates says that he must then be more clever than Daedalus because while Daedalus could only make his own works move, Socrates can make other people's works move.

Socrates is confusing Euthyphro. Euthyphro says that the words are moving around and that Socrates is like Deadelus. Socrates picks up on the Deadelus reference seemingly alluding to the fact that his deme was linked to Daedalus; and so the joke would be a good one were the claims being made Socrates' own. But since all of the claims are Euthyphro's--since in the early Platonic dialogues we get the genuine Socratic elenchus--Euthyphro must be the Daedalus. Euthyphro tacitly accepts that they are his words but insists that Socrates is the one making them move so he must be the Daedalus. That brings us to the end of the quoted passage. In the very next lines Socrates says that he must then be more clever than Daedalus because while Daedalus could only make his own works move, Socrates can make other people's works move.

OK, thanks. Unfortunately I'm still not quite sure I get it. Does Euthyphro mean that Socrates is making the significations of his words "move around" on their own, i.e. become ambiguous, much like how Daedalus caused the automata to move on their own? Is that the allusion?